The invisible jewelry setting is one of the more aesthetically pleasing and commercially popular jewelry settings available today. Gemstones placed within an invisible setting are secured to the setting at points beneath their crowns, so that the setting presents an unobstructed view of essentially all of the upper surface of the gemstone. The gemstones' crowns in turn receive more incoming, incident light than gemstones set in a comparable ordinary setting, increasing the stones' refractive fire or sparkle. As a result, the gemstones placed in an invisible setting are displayed to great effect to the jewelry's purchaser, wearer and viewer.
The lost wax casting technique is a widely known method for producing jewelry with invisible jewelry settings. Generally, the lost wax technique for producing jewelry involves producing wax model copies of a master setting, and mounting the gemstones in the wax model copies. Typically, the wax models are then encased in a liquid or slurry of investment material to form a mold. After the mold hardens, the wax is removed leaving the gemstones in the mold. The cavity in the mold left by the wax is then filled with a molten precious metal, such as a jewelry grade alloy of gold. The metal hardens as it cools, encasing and securing the gemstones in a jewelry setting that is nearly identical to the wax model used to produce the mold.
Thus, to apply this technique to produce a conventional invisible setting, the gemstones set into the wax models must precisely match those originally used in the master. In a conventional invisible setting, the gemstones are mounted upon fine protrusions that extend from an anchor on the setting floor into cavities cut into the gemstones. The step of mounting the stones in the wax model must be preceded by the step of cutting cavities within the gemstones that are identical to the cavities originally cut in the stones placed in the master setting. In addition, the wax models must be formed with anchors that precisely match the anchors in the master. The stones must then be carefully mounted on the wax anchors to avoid damaging their fine protrusions. Small variances in the wax models, damage to the anchors, or variation in the gemstones' size, shape or the pre-cut cavities can produce jewelry with improperly set gemstones. Since the anchors and cavities are entirely concealed within the wax model and setting after the gemstones have been placed, quality control of the conventional invisible settings during production can be problematic.
The conventional methods for producing conventional invisible settings are time consuming and require extensive use of highly skilled labor. The step of cutting grooves or other inclusions into the gemstones often requires the employment of a skilled lapidary. The step of mounting the gemstones on the wax model similarly should be performed with great care in order to avoid damage to the anchors, and a lapidary or jeweler is also typically required to perform this step.
Other methods for producing jewelry settings generally similar to the conventional invisible setting, such as those used to produce channel-style settings, do not produce settings with the same esthetic qualities of the conventional invisible setting. In these channel settings, several rows of gemstones are mounted in a series of adjacent rows or channels. Unfortunately, conventional methods for producing channel settings mount the stones in part using an interior wall between the rows that is clearly visible to the wearer and partially obstructs incident light.
For example, U.S. Pat. No. 6,516,864 discloses a method and tool for setting gems in a multiple channel setting where a groove is cut into the walls of the channels in the wax model instead of into the gems. The gems are snapped into place in the wax model by forcing them into the channel. The thickness of the walls is such that the walls are not damaged when the stones are forced into the channel. The grooves are also cut at different levels in the adjacent rows, so that the interior walls extend above the upper surface of at least one of the rows of stones. As a result, the wall between the rows of stones extends above the upper surface of at least some of the stones, partially obstructing the gemstones from incident light.
Although conventional invisible channel settings are also known, however, the methods for producing these settings entail the same problems as other conventional invisible settings. In particular, in a conventional invisible channel setting all of the girdles of the stones abut one another or the walls of the setting. Protrusions on anchors on the floor of the channel engage precisely cut grooves or other inclusions pre-cut on the pavilions of the gemstones, all of which are entirely concealed beneath the gemstone. As a result, the methods for producing conventional invisible channel settings have the same cost, labor and quality control problems as other conventional invisible channel settings.
Thus, there is a need in the art for a method of producing an effectively invisible setting that securely attaches gemstones to the setting in a cost effective manner despite minor variations in size and shape, and that still retains the pleasing and commercially valuable esthetics of a conventional invisible setting.